* fix: add way to skip clipboard tests when on CI/CD workflows

* fix: add -test.short argument on the test target run

This commit adds a shell script to easily install Clipper on Linux and macOS systems. The script determines the OS and architecture, downloads the appropriate binary from the GitHub releases, makes it executable, and installs it to /usr/local/bin. It also verifies the installation and provides informative logging messages throughout the process.

- Supports installation on Linux (x86_64, arm64) and macOS (x86_64, arm64).
- Uses mktemp to create a temporary directory for downloading the binary.
- Ensures the /usr/local/bin directory is available and in the user's PATH before installation.
- Provides clear error messages and feedback during each step of the installation process.

- Added installation instructions using the install.sh script for easier setup.
- Provided a direct command for users to install Clipper using curl and the install script.
- Ensured clarity in the manual installation and usage sections.

- Fix some grammar mistakes
- Rewrite the Features section
- Update Installation section adding wget and a warning note

- Updated main.go to allow specifying multiple file paths
- Concatenated content from multiple files before copying to clipboard
- Updated usage message to reflect new functionality

Extracted Content Parsing Logic: The parseContent function handles the logic of determining the content string based on the directText flag and file arguments.

Simplified Main Function: The main function is now more concise, focusing on flag parsing, calling parseContent, and handling the result.

Error Handling: The error handling is streamlined, with errors being returned from parseContent and handled in the main function.

- Handle each case in parseContent separately for clarity.
- Integrate the updated parseContent into the main.go.
- Ensure consistent error handling and function documentation.

- Add tests for `copyToClipboard` function to verify clipboard operations.
- Add tests for `readFromStdin` function to ensure proper stdin reading.
- Add tests for `readFromFile` function to verify file reading functionality.
- Add tests for `parseContent` function to check parsing of direct text input, stdin, and file inputs.

These tests enhance the robustness of the application by ensuring all core functionalities are working as expected.

- Add check for necessary tools (`curl`, `sudo`) before proceeding.
- Implement version check to fetch the latest release version from GitHub.
- Include comparison of installed and latest version to determine if an upgrade is needed.
- Add user prompts for confirmation to proceed with installation or upgrade.
- Implement uninstallation functionality.
- Add command line options: `-y` for auto-confirmation, `-h` for help message, `-r` for uninstallation, `-v` for version check.
- Ensure /usr/local/bin is in PATH before installing.
- Enhance error handling and provide consistent and informative error messages.
- Implement cleanup of temporary files after script execution.

* test(main_test.go): enhance unit tests with additional comments for better documentation

- Added detailed comments to each unit test function in main_test.go to explain the purpose and steps of the tests.
- Improved documentation to make it easier for future developers to understand the intent and functionality of the tests.
- TestParseContent_MultipleFiles: Verifies parseContent correctly concatenates contents of multiple files.
- TestParseContent_EmptyFiles: Verifies parseContent handles empty files gracefully.
- TestParseContent_EmptyInput: Ensures parseContent handles empty input gracefully.
- TestParseContent_InvalidFilePath: Checks how parseContent behaves with an invalid file path.
- TestParseContent_LargeFile: Verifies parseContent handles large files correctly.
- TestParseContent_DirectText: Verifies parseContent handles direct text input correctly.
- TestParseContent_Stdin: Verifies parseContent handles stdin input correctly.
- TestParseContent_File: Verifies parseContent handles file input correctly.
- Added utility functions createTempFile and replaceStdin with detailed comments.

Refactor tests to use t.TempDir() for automatic cleanup of temporary files.

* test(deps): add xyproto/randomstring package

Helps handling tests where the creation of random or large data is
neeeded.

* test(main_test): mark replaceStdin as a test helper

This marks replaceStdin as a helper, so when it fails, the error message will indicate the line in the test function that called it, rather than inside the helper itself. This makes debugging easier.

Co-authored-by: ccoVeille <3875889+ccoVeille@users.noreply.github.com>

* test(main_test): mark createTempFile as a test helper

This also marks createTempFile as a helper, so when it fails, the error message will indicate the line in the test function that called it, rather than inside the helper itself. This makes debugging easier.

Co-authored-by: ccoVeille <3875889+ccoVeille@users.noreply.github.com>

* test(main_test.go): explicitly declare directText

Make it clearer what is the use of the nil when testing parseContent

---------

Co-authored-by: ccoVeille <3875889+ccoVeille@users.noreply.github.com>